Atmospheric CO2 and CH4 Fluctuations over the Continent-Sea Interface in the Yenisei River Sector of the Kara Sea

Observations of the atmospheric sources and sinks carbon dioxide (CO2) methane (CH4) in pan-Arctic domain are extremely scarce, limiting our knowledge turnover this climatically sensitive environment fate enormous reservoirs conserved permafrost. Especially critical gaps high latitudes Siberia, covered by vast permafrost underlain tundra, where only several monitoring sites operational. This paper presents first two years (September 2018–January 2021) accurate continuous observations CO2 CH4 dry mole fractions at recently deployed tower-based measurement station “DIAMIS” (73.5068° N, 80.5198° E) located on southwestern coast Taimyr Peninsula, Gulf Yenisei River that opens to Kara Sea (Arctic Ocean). In paper, we summarized scientific rationale site, examined seasonal footprint with an analysis terrestrial vegetation maritime sector contributing captured signal, illustrated temporal patterns for daytime mixed layer over continent–sea interface. Along variations reflecting a signal caused not very much influenced local processes, analyzed spatiotemporal distribution synoptic anomalies representing signatures regional studied high-arctic Siberian ~625 thousand km2, nearly equal capturing land surface (54%) ocean (46%) throughout year. Both CH4, have observed sea–continent declining trend, presuming larger depletion trace gases air masses compared continental domain. So far, Sea, detected any prominent signals might indicated processes subsea degradation occurrence cold seeps–still mainly eastern Arctic Seas—The Laptev East-Siberian Sea.